package com.xuecheng.gateway.filter;

import com.alibaba.fastjson.JSON;
import com.xuecheng.commons.constants.UserConstants;
import com.xuecheng.commons.model.vo.AuthInfo;
import com.xuecheng.commons.utils.JwtUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.concurrent.TimeUnit;

@Component
@Slf4j
public class AuthFilter implements Ordered,GlobalFilter {

    @Autowired
    private RedisTemplate redisTemplate;

    //过滤拦截token
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //1.获取request和response对象
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();
        //2.放行部分URI(有些请求不登录也能访问)
        String path = request.getURI().getPath();
        if (path.contains("coursePub/preview") ||
                path.contains("auth/login") ||
                path.contains("baisc/dictionary") ||
                path.contains("category/tree-nodes") ||
                path.contains("course/upload") ||
                path.contains("search/") ||
                path.contains("payment/wx/notify")) {
            return chain.filter(exchange);
        }
        //3.获取请求头
        String token = request.getHeaders().getFirst("Authorization");
        //4.校验token
        Boolean verifyToken = JwtUtils.verifyToken(token);
        if (verifyToken == false) {
            response.setRawStatusCode(401); //权限不足，跳转登录页
            return response.setComplete(); // 直接拦截，并返回
        }
        //5.解析token
        AuthInfo authInfo = JwtUtils.getInfoFromToken(token);
        //6.判断token是否过期
        if (!redisTemplate.hasKey(UserConstants.USER_ID + authInfo.getUid())) {
            response.setRawStatusCode(401); // 权限不足，跳转登录界面
            return response.setComplete(); // 直接拦截并返回
        }
        //7.判断小于一小时续期
        Long expire = redisTemplate.getExpire(UserConstants.USER_ID + authInfo.getUid(), TimeUnit.HOURS);
        if (expire < 1) {
            redisTemplate.expire(UserConstants.USER_ID + authInfo.getUid(), 3, TimeUnit.HOURS);
        }
        try {
            // 8.将authInfo转为json,设置到payload请求头，实现路由转发
            String json = JSON.toJSONString(authInfo);
            // 解决中文乱码问题
            String encode = URLEncoder.encode(json, "UTF-8");
            ServerHttpRequest newRequest = request.mutate().header("payload", encode).build();
            // 将newRequest设置到exchange
            ServerWebExchange newExchange = exchange.mutate().request(newRequest).build();
            // 9.放行
            return chain.filter(newExchange);
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public int getOrder() {
        return 1;
    }
}
